Signal processing device for distributed antenna system

ABSTRACT

A signal processing device according to an exemplary embodiment of the inventive concept can integrate a power amplifier, a duplexer, and a linearizer as a module to improve the convenience of management and to improve flexibility and extensibility so as to be transformable corresponding to a change in system development concept.

CROSS REFERENCE TO RELATED APPLICATION

This is a Continuation of U.S. application Ser. No. 15/395,720, filed onDec. 30, 2016, which is a Continuation-in-Part of InternationalApplication No. PCT/KR2015/005130, filed May 22, 2015, the contents ofwhich are incorporated herein by reference in their entireties.

BACKGROUND 1. Field

The inventive concept relates to a signal processing device. Morespecifically, the inventive concept relates to a signal processingdevice that can improve the convenience of management by integrating apower amplifier, a duplexer, and a linearizer as a module and improveflexibility and extensibility so as to be transformable corresponding toa change in system development concept.

2. Description of Related Art

Mobile communication usage of users has been rapidly increased due todevelopment of mobile communication and the users want to stably receivea communication service without the constraints of time and space.However, it is difficult for an operator to smoothly provide thecommunication service to the users while a shadow area is generated dueto a limited output of a base station and a constraint such as theposition or a peripheral geographical feature of the base station, andas a scheme for resolving such a problem, a distributed antenna system(DAS) is used.

The DAS is installed in an area in which a radio wave is not received orweakly received, such as the inside of a building, a basement of thebuilding, a subway, a tunnel, an apartment complex of a residentialarea, a stadium, or the like, to provide the communication service up tothe shadow area where a signal of the base station is difficult to reachand extend coverage of the base station, and consists of a headendapparatus that that is communicatively connected with the base stationand a plurality of remote apparatus that is connected to the headendapparatus through a optical transport medium and is communicativelyconnected to a user terminal to process a signal.

In the plurality of remote apparatus of the DAS according to the relatedart, there are a lot of cases in which a deployment state of a poweramplifier, a duplexer, and a linearizer or whether the power amplifier,the duplexer, and the linearizer are provided is decided according to adevelopment concept of the system, and as a result, the system cannot beunited and it is thus difficult to manage the plurality of remoteapparatus and it is also difficult to efficiently cope with a change inoperational environment of the system.

SUMMARY

The inventive concept relates a signal processing device that canimprove the convenience of management by integrating a power amplifier,a duplexer, and a linearizer as a module and can also improveflexibility and extensibility so as to be transformable corresponding toa change in system development concept.

According to an exemplary embodiment of the inventive concept, there isprovided a signal processing device including: a base module including apower amplifier; a first module coupled to the base module andselectively including an RF processing unit for processing an RF signal;a circuit substrate detachably coupled to the first module and includinga linearizer correcting a distortion signal; and a second modulecovering the first module and including a duplexer separating atransmitted or received RF signal.

An accommodating groove accommodating the circuit substrate may beformed on one surface of the first module.

A first connector transferring a signal processed and introduced by theRF processing unit to the linearizer, and a second connectortransferring the signal processed through the linearizer to the poweramplifier may be provided on one surface of the first module.

The linearizer may include a pre-distortion device.

The signal processing device may further include a sensing unit providedin the first module to sense whether the circuit substrate is mounted ordetached.

The signal processing device may further include a switch unit switchingthe signal processed by the RF processing unit to be processed by thelinearizer and thereafter, transferred to the power amplifier at thetime of mounting the circuit substrate according to a detection ofwhether the circuit substrate is mounted or detached by the sensingunit.

The switch unit may switch the signal introduced into the signalprocessing device to be bypassed to the power amplifier at the time ofseparating the circuit substrate according to a detection of whether thecircuit substrate is mounted or detached by the sensing unit.

A signal processing device according to an exemplary embodiment of theinventive concept can improve the inconvenience of management byintegrating a power amplifier, a duplexer, and a linearizer as a moduleand easily replacing or separating parts as necessary, and also canimprove flexibility and extensibility so as to be transformablecorresponding to a change in system development concept.

BRIEF DESCRIPTION OF FIGURES

The above and other aspects, features and advantages of certainexemplary embodiments of the inventive concept will be more apparentfrom the following description taken in conjunction with theaccompanying drawings, in which:

FIG. 1 is an exploded perspective view of a signal processing deviceaccording to an exemplary embodiment of the inventive concept;

FIG. 2 is a perspective view of the signal processing device accordingto the exemplary embodiment of the inventive concept;

FIG. 3 is a diagram schematically illustrating a first module of thesignal processing device according to the exemplary embodiment of theinventive concept; and

FIGS. 4 to 6 are usage state diagrams to which the signal processingdevice according to the exemplary embodiment of the inventive concept isapplied.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

The inventive concept may have various modifications and variousexemplary embodiments and specific exemplary embodiments will beillustrated in the drawings and described in detail through the detaileddescription. However, this is not intended to limit the inventiveconcept to the specific exemplary embodiments, and it should beunderstood that the inventive concept covers all the modifications,equivalents and replacements included in the spirit and technical scopeof the inventive concept.

In describing the inventive concept, when it is determined that thedetailed description of the publicly known art related to the inventiveconcept may unnecessarily obscure the gist of the inventive concept, thedetailed description thereof will be omitted. Further, numerical figures(for example, first, second, and the like) used during describing thespecification are just identification symbols for differentiating onecomponent from other components.

Further, in the specification, when it is mentioned that one element is“connected with” or “accesses” the other element, the one element may bedirectly connected with or directly accesses the other element, but ifthere is a not particularly contrary description, it should beappreciated that both elements may be connected with or accesses eachother with another element intervening therebetween.

In addition, a term “˜part (unit)”, ˜er”, “˜or”, “˜module”, or the like,described in the specification means a unit of processing at least onefunction or operation and may be implemented by hardware or software ora combination of hardware and software.

In addition, it will be apparent that in the specification, componentsare just classified for each main function which each component takescharge of. That is, two or more components to be described below may beprovided to be combined into one component or one component may beprovided to be separated into two or more for each of more subdividedfunctions. In addition, each of the components to be described below mayadditionally perform some or all functions among functions which othercomponents take charge of in addition to the main function which eachcomponent takes charge of, and some functions among the main functionswhich the respective components take charge of may be exclusivelycharged and performed by other components, of course.

A distributed antenna system means a coverage system for an in-buildingservice that transfers voice communication and data communication withhigh quality for seamlessly accessing and means a system for servicingan analog and digital telephone system which is serviced in multiplebands through at least one antenna. Further, the distributed antennasystem may enhance a poor radio wave environment in building and enhancea poor received signal strength indication (RSSI) and chip energy/othersinterference (Ec/Io) which is total receiving sensitivity of a mobileterminal.

Meanwhile, a distributed antenna system using a signal processing deviceaccording to an exemplary embodiment may support a mobile communicationstandard which is used worldwide. For example, the distributed antennasystem may support frequencies such as a very high frequency (VHF), anultra high frequency (UHF), 700 MHz, 800 MHz, 850 MHz, 900 MHz, 1900MHz, 2100 MHz band, 2600 MHz band, and the like, and an FDD-schemeservice and a TDD-scheme service. In addition, the distributed antennasystem may support an advanced mobile phone service (AMPS) which is arepresentative of analog and multiple mobile communication standardssuch as Time-Division Multiplexing Access (TDMA), Code Division MultipleAccess (CDMA), Wideband Code Division Multiple Access (WCDMA), HighSpeed Downlink Packet Access (HSDPA), Long Term Evolution (LTE), LongTerm Evolution Advanced (LTE-A), and the like of digital.

Hereinafter, exemplary embodiments of the inventive concept will bedescribed in detail with reference to the accompanying drawings.

FIG. 1 is an exploded perspective view of a signal processing deviceaccording to an exemplary embodiment of the inventive concept. FIG. 2 isa perspective view of the signal processing device according to theexemplary embodiment of the inventive concept. FIG. 3 is a diagramschematically illustrating a first module of the signal processingdevice according to the exemplary embodiment of the inventive concept.FIGS. 4 to 6 are usage state diagrams to which the signal processingdevice according to the exemplary embodiment of the inventive concept isapplied.

In FIGS. 1 to 6, a base module 10, a power amplifier 11, a firstterminal 15, a first module 20, an RF processing unit 21, aaccommodating groove 23, a first connector 25, a second connector 27, aswitch unit 29, a circuit substrate 30, a linearizer 31, a second module40, a duplexer 41, a handle 43, a second terminal 45, a connection line47, a low-noise amplifier 51, and a gain control unit 53 areillustrated.

Referring to FIG. 1, the signal processing device according to theexemplary embodiment includes: a base module 10 including the poweramplifier 11; a first module 20 coupled to the base module 10 andselectively including the RF processing unit 21 for processing an RFsignal; a circuit substrate 30 detachably coupled to the first module 20and including the linearizer 31 compensating a distortion signal; and asecond module 40 covering the first module 20 and including the duplexer41 separating a transmitted or received RF signal to improve theconvenience of management by integrating the power amplifier 11, theduplexer 41, and the linearizer 31 as a module and to improveflexibility and extensibility so as to be transformable corresponding toa change in system development concept.

A distributed antenna system (DAS) may include a headend apparatus (notillustrated), which is communicatively coupled to a base station andconstitutes a headend node, and a hub apparatus serving as an extensionnode, and a plurality of remote apparatus respectively disposed atremote service location. The distributed antenna system (DAS) may beimplemented as an analog distributed antenna system. However, thetechnical spirit of the inventive concept is not limited thereto. Thedistributed antenna system (DAS) may be implemented as a digitaldistributed antenna system and in some cases, implemented as a mixedtype (for example, some nodes perform analog processing and residualnodes perform digital processing) thereof. The signal processing deviceaccording to an exemplary embodiment of the inventive concept may bemounted in at least one of the remote apparatus for processing a signalhaving a predetermined frequency band. According to one or moreimplementations, if the distributed antenna system (DAS) has employed aneutral host architecture to integrally support various services (e.g.,multi-band services, multi-carrier services, etc.) or services of aplurality of providers, a plurality of the signal processing device maybe mounted in the remote apparatus for a predetermined frequency band.

The signal processing device according to the exemplary embodiment mayinclude a base module 10, the first module 20, the circuit substrate 30,and the second module 40.

The base module 10 may be coupled to the first module 20 to be describedbelow and may include the power amplifier 11. The power amplifier 11 mayamplify a transmission signal to transmit the amplified transmissionsignal to the duplexer 41 to be described below.

The first module 20 may be coupled to the base module 10 and mayselectively include the RF processing unit 21. The first module 20 maybe coupled to the top of the base module 10 and may selectively includethe RF processing unit 21 for processing a radio frequency (RF) signal.In the exemplary embodiment, it is described that the base module 10 andthe first module 20 are configured as separate parts, respectively andthe first module 20 is coupled to the top of the base module 10, but thebase module 10 and the first module 20 are formed as one component, andas a result, the power amplifier 11 and the RF processing unit 21 may beprovided therein.

The RF processing unit 21 may be selectively provided in the firstmodule 20. That is, when it is determined that the RF processing unit 21is required according to a system development concept, the RF processingunit 21 may be provided in the first module 20 and, when the RFprocessing unit 21 is not required or a separate RF processing unit 21is provided outside the signal processing device, the RF processing unit21 may not be provided in the first module 20. The RF processing unit 21which is used to process a transmitted RF signal may be an RF-IFconversion device that converts the RF signal into an intermediatefrequency (IF) signal. In general, since the RF signal transmitted fromthe base station is a high-power signal, the RF signal is converted intoa signal having appropriate power through the RF processing unit 21.However, when the RF processing unit 21 is a component that may processthe RF signal, the RF processing unit 21 may be configured in variousschemes.

Meanwhile, the low-noise amplifier (LNA) 51 and the gain control unit(gain block) 53 used in a reverse-direction link may be provided in thefirst module 20. Noise of a signal transferred through the duplexer 41may be removed and power of the signal may be controlled while passingthrough the low-noise amplifier 51 and the gain control unit 53 to beoutput to the outside of the signal processing device (see FIGS. 4 to6).

The circuit substrate 30 may be detachably coupled to the first module20 and may include the linearizer 31 that compensates a distortionsignal. The circuit substrate 30 may be detachably coupled to the top ofthe first module 20 and mounted on the signal processing device asnecessary. The linearizer 31 may be provided in the circuit substrate 30to correct and linearize the distortion signal. The linearizer 31 mayinclude a pre-distortion device. In this case, the pre-distortion devicemay be an analog pre-distortion (APD) device or a digital pre-distortion(DPD) device.

In detail, when the circuit substrate 30 is mounted on the signalprocessing device, the signal processed by the RF processing unit 21 istransmitted to the linearizer 31 of the circuit substrate 30 and thetransmitted signal is compensated by the linearizer 31 and transmittedto the power amplifier 11. On the contrary, when the linearizer 31 isnot required and the circuit substrate 30 including the linearizer 31 isnot mounted on the signal processing device according to the systemconcept, the signal introduced into the signal processing device istransmitted to the power amplifier 11. Further, since an external inputsignal is an IF signal, when a separate RF-IF conversion device is notrequired in the signal processing device, the RF processing unit 21 maynot be provided in the first module 20. As such, in the signalprocessing device according to the exemplary embodiment, since thecircuit substrate 30 including the linearizer 31 may be mounted/detachedaccording to the system development concept, flexibility andextensibility may be improved as the signal processing device.

The second module 40 may cover the first module 20 and the second module40 may include the duplexer 41 that separates the transmitted orreceived RF signal. The handle 43 is provided on the top of the secondmodule 40 to facilitate transportation or installation of the integratedsignal processing device. Meanwhile, a first terminal 15 may be formedat one side of the base module 10 and a second terminal 45 may be formedat one side of the second module 40, and the first terminal 15 and thesecond terminal 45 may be connected by the connection line 47.

As such, the power amplifier 11, the duplexer 41, the linearizer 31, andthe RF processing unit 21 may be integrated as the module, and parts mayeasily be replaced and detached as necessary to improve the convenienceof management.

The accommodating groove 23 accommodating the circuit substrate 30 maybe formed on one surface of the first module 20. The accommodatinggroove 23 may be formed on the top of the first module 20 so as tocorrespond to the circuit substrate 30, and the circuit substrate 30 maybe inserted into the accommodating groove 23 to be provided in thesignal processing device integrally with the first module 20.

In this case, a first connector 25 and a second connector 27 may beformed on one surface of the first module 20.

Referring to FIG. 3, the first connector 25 is formed on one surface ofthe first module 20, and as a result, the signal processed andintroduced by the RF processing unit 21 is transferred to the linearizer31. The second connector 27 is formed on one surface of the first module20 to be separated from the first connector 25 to transfer the signalprocessed through the linearizer 31 to the power amplifier 11.

Meanwhile, the signal processing device according to the exemplaryembodiment may further include a sensing unit provided in the firstmodule 20 to sense whether the circuit substrate 30 is detachable. Thesensing unit may determine whether the circuit substrate 30 is mountedor detached according to whether the circuit substrate 30 contacts thefirst module 20. The sensing unit is provided in the first module 20 andactuates the switch unit 29 to be described below by detecting whetherthe circuit substrate 30 is mounted or detached to control the signalintroduced into the first module 20.

The switch unit 29 may switch the signal processed by the RF processingunit 21 to be processed by the linearizer 31 and thereafter, transferredto the power amplifier 11 at the time of mounting the circuit substrate30 according to a detection of whether the circuit substrate 30 ismounted or detached. Further, the switch unit 29 may switch the signalintroduced into the signal processing device to be bypassed to the poweramplifier 11 at the time of separating the circuit substrate 30according to a detection of whether the circuit substrate 30 is mountedor detached. In detail, when the circuit substrate 30 is mounted, thesignal processed by the RF processing unit 21 is introduced into thelinearizer 31 of the circuit substrate 30 through the first connector 25and the signal processed by the linearizer 31 is transferred to thepower amplifier 11 through the second connector 27. Meanwhile, when thesensing unit senses that the circuit substrate 30 is detached from thefirst module 20, the switch unit 29 operates to bypass the input signalintroduced into the signal processing device and transfer the bypassedinput signal to the power amplifier 11.

FIGS. 4 to 6 are usage state diagrams to which the signal processingdevice according to the exemplary embodiment of the inventive concept isapplied.

Referring to FIG. 4, the exemplary embodiment shows a case in which theRF processing unit 21 and the linearizer 31 are required in the signalprocessing device according to the system concept, the RF processingunit 21 is provided in the first module 20, and the circuit substrate 30including the linearizer 31 is mounted on the top of the first module20. The signal introduced into the RF processing unit 21 is subjected tosignal processing such as frequency conversion by the RF processing unit21 to be transferred to the linearizer 31. The signal transferred to thelinearizer 31 is compensated by the linearizer 31 and transferred to thepower amplifier 11. The signal transferred to the power amplifier 11 isamplified by the power amplifier 11 and thereafter, transferred to anantenna (not illustrated) through the duplexer 41. In this case, the RFprocessing unit 21 may be an RF-IF conversion device for converting theRF signal into the IF signal and the linearizer 31 may be a linearizerincluding the pre-distortion device for correcting the converted IFsignal.

Referring to FIG. 5, the exemplary embodiment shows a case in which thelinearizer 31 not including the pre-distortion device is required in thesignal processing device according to the system concept, and the RFprocessing unit 21 is not provided in the first module 20 and thecircuit substrate 30 including the linearizer 31 is mounted on the topof the first module 20. The input signal is transferred to thelinearizer 31 and the signal transferred to the linearizer 31 iscorrected and transferred to the power amplifier 11. The signaltransferred to the power amplifier 11 is amplified by the poweramplifier 11 and thereafter, transferred to an antenna (not illustrated)through the duplexer 41.

Referring to FIG. 6, an exemplary embodiment shows a case in which thelinearizer 31 is not required in the signal processing device accordingto the system concept and the RF processing unit 21 is not provided inthe first module 20 and the linearizer 31 is not also provided. Thesensing unit determines whether the circuit substrate 30 is separatedfrom the first module 20 according to whether the circuit substrate 30contacts the first module 20 and the switch unit 29 switches the signalto bypass the input signal introduced into the signal processing deviceto the power amplifier 11.

As described above, the signal processing device according to theexemplary embodiment may integrate the power amplifier 11, the duplexer41, and the linearizer 31 as the module to improve the convenience ofthe management and improve the flexibility and extensibility so as to betransformable corresponding to the change in system development concept.

Hereinabove, the inventive concept has been described in detail withreference to the preferred embodiment, but the inventive concept is notlimited to the embodiment and various modifications and changes may bemade by those skilled in the art within the technical spirit and scopeof the inventive concept.

What is claimed is:
 1. A signal processing apparatus comprising: a basemodule including a power amplifier; a first module coupled to the basemodule and selectively including an RF processing unit for processing anRF signal; a circuit substrate detachably coupled to the first module;and a second module covering the first module and including a duplexerseparating a transmitted or received RF signal.
 2. The signal processingapparatus of claim 1, wherein the circuit substrate includes alinearizer.
 3. The signal processing apparatus of claim 2, wherein thelinearizer is a pre-distorter.
 4. The signal processing apparatus ofclaim 2, wherein a first connector transferring a signal processed andinputted by the RF processing unit to the linearizer, and a secondconnector transferring the signal processed through the linearizer tothe power amplifier are provided on one surface of the first module. 5.The signal processing apparatus of claim 2, further comprising: asensing unit provided in the first module to sense whether the circuitsubstrate is mounted or detached.
 6. The signal processing apparatus ofclaim 5, further comprising: a switch unit switching the signalprocessed by the RF processing unit to be processed by the linearizerand thereafter, transferred to the power amplifier at the time ofmounting the circuit substrate according to a detection of whether thecircuit substrate is mounted or detached by the sensing unit.
 7. Thesignal processing apparatus of claim 6, wherein the switch unit switchesthe signal inputted into the signal processing apparatus so as to bebypassed to the power amplifier at the time of detaching the circuitsubstrate according to a detection of whether the circuit substrate ismounted or detached by the sensing unit.
 8. A signal processingapparatus comprising: a first module including an RF circuitry forprocessing an RF signal; and a second module covering the first moduleand including a duplexer separating a transmitted or received RF signal.9. The signal processing apparatus of claim 8, wherein the RF circuitryincludes at least one of a power amplifier, a low-noise amplifier and again controller.
 10. The signal processing apparatus of claim 8, furthercomprising a circuit substrate detachably coupled to the first module,and wherein an accommodating groove accommodating the circuit substrateis formed on one surface of the first module.
 11. The signal processingapparatus of claim 10, wherein the circuit substrate is interposedbetween the first module and the second module.